The first design principle is "fast to the fun." You can jump in right away with no registration or anything and find out right away if your thing or not. It's a mix of arcade style action with rogue-like elements:

Large number of power-ups and boosts from gems, magic items, leveling up, etc.

Lost Crypts is a multiplayer coop dungeon runner infusing elements of Roguelikes and the arcade classic "Gauntlet." Up to four players descend through the crypts gathering treasures and battling hordes of monsters and avoiding traps. The game is played in a browser and requires Flash, a keyboard and mouse.

Features:

* Play as one of three classes with different stats and special attacks.

The game has been in development since the beginning of the year (2013) and is now in Open Beta. While the core game play is not likely to change, there will be changes and new features based on player feedback.

So let me know how I can make the game better! I'm particularly interested in ways to improve player retention (i.e., repeat sessions) but also general feedback is always appreciated.

My project (Lost Crypts) is a coop Flash dungeon runner, mixing elements of Gauntlet and Rogue. Right now, the core loop works. There's always room for improvement, but the general consensus among play testers is that it is fun.

I talked with someone who is an expert in monetization for these kinds of games and his primary concern was retention and player investment. Right now, the "outer game" loop is relatively weak. You can unlock deeper levels and get on the high score list, but apart from that there's not much to make players come back for the next session.

I have a couple ideas for improving this and I'm looking for suggestions on how to improve them or other ideas:

1.) A mechanism for carrying items to the next life. So if you find a good item, you won't automatically lose it when you die. E.g., if you find a "Last Will" in the dungeon, one of your magic items will pass to your next character.

2.) An achievement progress system. Similar to quests or challenges, players will be able to unlock tiers by completing achievements:

There will be a set of possible achievements for each tier (e.g., reach level 10, kill 7 monsters in 1 second, etc, find a special item, etc.)

If a player completes 7 of them, they unlock the tier.

This will give a permanent reward and their character portrait will show a background indicating the highest tier they've reached and they can start working on the next tier. So every time the player plays, they are potentially making progress.

The permanent rewards will be in-game useful. For example, the first tier might be the tavern and once unlocked the player always starts with 1 food.

Ideas for other outer loop mechanics? Problems or improvements to these ideas?

This is partially a design question, but it's one driven by the realities of networked play.

I'm developing a Flash, multiplayer coop game, very similar to Gauntlet. One issue that I foresee being a problem is more than one player going for the same object (say a potion).

In order to make the game feel as responsive as possible, players' entities are moved locally on the client instantly, with the server only correcting the player if they did something impossible. Most of the time this isn't an issue, but where it will be an issue is if two players both try to pick up the same potion. The server currently will give the potion to whichever player arrives at the potion first, but from a player's perspective they may see the potion go to another player who seems farther from it.

I expect this will be annoying to the players and look like an unfair bug.

I've thought of one solution: have objects "drop" from an entity (like a chest). Every player will see the object and every player will be allowed to pick up the same object (possibly within a time limit). The object will only disappear from the client's view once they pick it up or the time limit expires.

Anyone know of a good resource (or tutorial) for creating art for a top-down 2D game? Usually when creating my programmer art I just google some images for guidance, but images/artwork tend to from a side-on view.